Coffee Science (E-Journal)
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Effect of Oxidative and Non-Oxidative Media on Coffee Torrefaction and Uncondensed-Gas Properties
Full text linkThis research aims to examine the effect of atmospheric media variations on the uncondensed gas characteristics produced from the torrefaction and cooling processes of coffee beans. The process involved using air, N2, and Ar at a speed of 1 l/min as atmospheric media. Arabica green beans were torrefied for 60 min at 235±8oC and later cooled at the same rate and medium in a fixed-bed torrefier but stopped after the temperature reached 50oC. The volatile gases from the process flowed to the condenser, followed by the separation of the uncondensed gas from the liquid product, and subsequently flowed through the chimney. Furthermore, thermocouples that are connected to the Artisan visual roaster scope as an interface as well as the Artisan 2.4.2 software on a computer to measure and record changes in drum and bean temperatures (oC) over time (min). The uncondensed-gas yield was calculatedaccording to the mass balance principle, and their characteristics were determined directly in the form of temperature distribution (oC) and CO emission (ppm) by placing the testo 310 gas analyser sensor on the chimney. According to the findings, oxidative atmospheric caused greater temperature fluctuations in the drum and beans during the processes than non-oxidative media. The variations in atmospheric media led to differences in yield, and uncondensed-gas temperature distribution, as well as the CO emission. There was an increase in CO emission as the temperature was increased. The CO produced from torrefaction using non-oxidative is lower than using oxidative media. The cost factor and supporting of absorbent uncondensed-gas recycling technology must be taken into account when using non-oxidative media. This application will not only yield product variants but also reduce CO emissions and the coffee industry’s carbon footprint.
Key words: Arabica-green-bean; coffee torrefaction; nitrogen; argon; condenser
Impact of mass-to-volume ratios on beverage quality in coffee blends
Full text linkThe discrimination of sensory attributes in coffee blends is complex due to the subjective nature of panelist evaluations and the intrinsic chemical heterogeneity of each variety. This study focuses on the influence of blend composition on the sensory evaluation of Robusta coffee, particularly its bitterness and astringency, depending on the proportion used. For specialty and commercial arabica coffees, positive attributes such as flavor and appearance are emphasized. The study also considers the impact of preparation concentrations, specifically the ratio of ground coffee (in grams) to water (in milliliters). We investigate coffee blends composed of different proportions of commercial roasted and ground Arabica coffee (CAC), Robusta coffee (RC), and a genotype of the Arabica specialty coffee (ASC) of the cultivar Yellow Bourbon, processed by both dry and wet methods. The blends were prepared at two concentrations: 7% (70 g ground coffee per 1,000 mL of water) and 10% (100 g ground coffee per 1,000 mL of water). Through predictive statisticalmodeling, this research investigates the sensory outcomes of coffee blends, considering implications previously associated with chemical variables in the literature. It was found that blends prepared at 10% concentration (m/v) with intermediate proportions of CAC and RC achieved a balance in bitterness and flavor attributes for both dry and wet processed Yellow Bourbon. Including brew concentration in the models improved predictive power substantially, increasing R² from approximately 75% to over 90%. Therefore, this concentration can be recommended to ensure a balanced sensory profile without disproportionate influence from any single attribute.
Key words: Arabica coffee; robusta coffee; sensory analysis; mixture models; simplex regression
Revealing the Arcs of Integration in the Coffee Supply Chain
Full text linkThe coffee industry plays a vital role in Indonesia’s rural economy, engaging millions of smallholder farmers and various downstream actors across the supply chain. However, the level of integration among these stakeholders remains uneven, influencing both efficiency and competitiveness. This study examines the integration levels within the coffee supply chain in Indonesia, utilizing the concept of Arcs of Integration. By analyzing the relationship between stakeholders within the supply chain, we identify five integration categories: inward-facing, periphery-facing, supplier-facing, customer-facing, and outward-facing. Data collected from 192 farmers and 40 downstream stakeholders from four provinces were analyzed using factor analysis, and discriminant analysis was employed to validate the classification of stakeholders based on their level of integration. The results indicate that the majority of stakeholders fall within the periphery-facing category, indicating moderate integration with suppliers and customers. This suggests that stakeholders in theIndonesian coffee supply chain often engage in transactional relationships rather than strategic, long-term collaborations. The study highlights the need for deeper integration among all stakeholders to enhance the efficiency, innovation, and competitiveness of the coffee supply chain, by working more closely together through joint business groups, cooperatives, and partnerships between farmers and lead firms.
Key words: Arcs of integration; coffee; Indonesia; periphery-facing, supply chain integration
Avaliação do desenvolvimento vegetativo e do comportamento de mudas de café (Coffea arabica) infectadas ou não por uma população fluminense de Meloidogyne exigua
Full text linkCoffee is one of the main commodities of the State of Rio de Janeiro and, among other problems, the damage caused by Meloidoyne exigua Goeldi, 1887, hinders the expansion of coffee in the State. The production of seedlings by hypocotyledonary grafting solves this problem, since it combines the resistance of Coffea canephora Pierre ex Froehn. to M. exigua to the quality and productivity of C. arabica L. Despite practiced in São Paulo, the hypocotyledonary grafting has not been validated in the conditions present in the State of Rio de Janeiro and neither the resistant genotypes were tested with populations of M. exigua belonging to the State, potentially different because of the genetic variability of this species. In this work was evaluated under greenhouse conditions the development of seedlings of four genotypes of coffee in non-grafted or grafted on ‘IAC Apoatã 2258’, infested or not with M. exigua. ‘IAC Obatã’ in non-grafted and ‘Iapar 59’ grafted had stood out with good vegetative growth. ‘IAC Obatã’, ‘IAC Red Catuaí 144’ and ‘IAC Tupi’ were susceptible to the fluminense population of M. exigua, while ‘IAC Apoatã 2258’ and ‘Iapar 59’ showed resistance, although allowed small reproduction of the nematode.O café é um dos principais produtos agrícolas do Estado do Rio de Janeiro. Dentre outros problemas, os danos provocados por Meloidogyne exigua Goeldi, 1887 dificultam a expansão da cafeicultura no Estado. A produção de mudas por enxertia hipocotiledonar contorna esse problema, associando a resistência de Coffea canephora Pierre ex Froehn. a M. exigua à qualidade e produtividade de C. arabica L. Não obstante, praticada em São Paulo, a enxertia hipocotiledonar não foi ainda validada nas condições fluminenses nem os genótipos ditos resistentes foram testados frente às populações fluminenses de M. exigua, potencialmente distintas devido à variabilidade genética dessa espécie. Neste trabalho avaliou-se em casa-de-vegetação o desenvolvimento de mudas de quatro genótipos de café em pés francos ou enxertadas sobre ‘IAC Apoatã 2258’, infestados ou não por M. exigua. Destacaram-se ‘IAC Obatã’ em pé-franco e ‘Iapar 59’ enxertado, com bom desenvolvimento vegetativo. ‘IAC Obatã’, ‘IAC Catuaí Vermelho 144’ e ‘IAC Tupi’ foram suscetíveis à população fluminense de M. exigua, enquanto ‘IAC Apoatã 2258’ e ‘Iapar 59’ comportaram-se como resistentes, embora permitindo pequena reprodução do nematóide
The Influence of Robusta Coffee Grounds Proportion and Fermentation Time on The Quality of Bokashi
Full text linkThis research aimed to study the influence of robusta coffee grounds proportion as a mixture of raw materials for bokashi production and fermentation time on the quality of the bokashi. This research was conducted using a Completely Randomized Design with two factors and two replications. The first factor was the proportion of coffee grounds (A; 0, 10, 20, 30%), and the second was fermentation time (F; 0, 10, 20 days). Fish bone meal was added constantly to each sample as much as 5%. The analysis carried out on bokashi included microbial properties (total colony counts; TCC), temperature, chemical properties (pH value, water content, C, N, C/N ratio), descriptive organoleptic test (texture, colour, aroma), and plant growth test. The results showed that bokashi, with the addition of coffee grounds had better pH value, C content, and plant height, while worse in N content and C/N ratio. However, the C/Nratio value still met the standard (<20). There was no difference in pH, C, N, C/N ratio, and plant height among coffee grounds addition of 10% to 30%. The organoleptic characteristics of bokashi generally tend to be improved with fermentation time, although there was no difference among F2 and F3. The two best bokashi, namely A2F3 (10% coffee grounds and 20 days of fermentation) and A3F3 (20% coffee grounds and 20 days of fermentation) had similar characteristics, but A3F3 was the best since it had very significantly better plant height. The best experimental condition for the production of the bokashi was 20% coffee grounds proportion with 20 days of fermentation time.
Key words: Coffee waste; organic waste; biodecomposer; bokashi; C/N ratio
Impact of Initial Moisture on Roasting and Sensory Profile of (Coffea arabica L.) from the State of Mexico
Full text linkThe coffee-producing municipalities of the State of Mexico cultivate this fruit at an altitude ranging from 1700 to 2100 meters above sea level, giving it the distinction of high-altitude coffee. Indeed, coffee from the State of Mexico has received the designation of “quality coffee,” receiving awards received at the national “Taza de Excelencia México” competition in recent years. However, no studies have been conducted in the region on the standardization of the bean drying process before roasting, nor on its impact on the sensory profile. Therefore, the objective of this study was to evaluate the effect of the coffee bean initial moisture from the State of Mexico on the roasting process and the cup profile. In 2023, coffee (Coffea arabica L., Caturra rojo variety) was harvested and processed through a natural method. After drying, it was divided into 800-gram treatments of green coffee with different moisture percentages (10, 11, 12, 13, and 14%), and then roasted according to the 2023 Specialty Coffee Association protocol. The roasted coffee was evaluatedusing a sensory analysis based on the protocol of the same association, where 10 sensory attributes were assessed. The cupping indicated that the 13% moisture treatment yielded the highest scores, presenting medium-high fragrance notes, sweetness, and fruity characteristics, along with sweet notes of brown sugar. However, this moisture content poses a risk, as it allows the development of microorganisms that can damage the bean. All samples received sensory quality scores ≥80, classifying them as “specialty coffees.
Key words: Altitude; specialty coffee; sensory evaluation; moisture initial.
Efeito da densidade e da distância de Brachiaria decumbens Staff sobre o crescimento inicial de mudas de Coffea arabica L.
Full text linkThe aim of this work was to evaluate the interference of three densities (4, 8 and 16 plants/m2) of Brachiaria decumbens Stapf distributed at three different distances (0, 10 and 20 cm from coffee plants) on the initial growth of Coffea arabica L. seedlings. Dark red Latosoil was used as substrate to fill up 70 liters cement boxes. Coffee seedlings at 15 cm height and 8 leaves stage were planted in each box. B. decumbens seedlings were transplanted when they reached two to four leaves stage. The experimental design was a randomized blocks with ten treatments and three replications. At the end of the experiment were measured, height, leaf number, leaf area, chlorophyll content and dry weight of coffee plants. Dry weight of B. decumbens leaves was also evaluated. The leaf area and leaf dry weight was shown to be more sensitive parameters to the interference of Brachiaria plants. Dry weight of coffee plants were reduced from 60% to 88% when the B. decumbens were transplanted 0 cm from the coffee plant. With distance of 10 cm the reduction of dry weight increased with the increase of the density of the B. decumbens. In the coexistence of the coffee plants with 16 plants/m2 of B. decumbens, there was a reduction in the dry weight of about 80% at the distances of 0 and 20 cm. Regarding leaf area, the reduction was 47% on the average in the density of 4 plants/m2 of B. decumbens The reduction in leaf area at other densities was higher at the distance of 0 and 20 cm, and 55% reduction was obtained at the distance of 10 cm. Objetivou-se estudar, através deste trabalho, a interferência da densidade da Brachiaria decumbens Stapf (4, 8 e 16 plantas/m2), em três distâncias (0, 10 e 20 cm das plantas de café), no crescimento inicial de mudas de Coffea arabica L. Uma muda de café foi transplantada no centro de caixas de 70 L e o capim-braquiária foi transplantado de acordo com o tratamento. O delineamento experimental adotado foi em blocos casualizados, em esquema fatorial 3 (densidades) x 3 (distâncias) +T (sem braquiária), em três repetições. A área foliar e a massa seca das folhas do cafeeiro se mostraram mais sensíveis à interferência. Quando o capim-braquiária foi plantado junto à muda (0 cm), provocou uma redução de 60% a 88% na massa seca do cafeeiro. Com distância de 10 cm a redução de massa seca aumentou com o aumento da densidade da braquiária. Na convivência do cafeeiro com 16 plantas/m2 de capim-braquiária, a redução de massa seca foi de 80% nas distâncias de 0 e 20 cm. Em relação à área foliar, a redução foi em média 47% na densidade de 4 plantas/m2 de capim-braquiária e nas demais densidades a redução foi maior nas distâncias de 0 e 20 cm.
Extraction and Purification of Xylooligosaccharides from Coffee Peel Using Endo-β-1,4-D-Xylanase XynBTN63D and Adsorption for Prebiotics
Full text linkThis research aims to extract and purify xylooligosaccharides (XOS) from coffee peel xylan using recombinant endo-β-1,4-D-xylanase (XynBTN63D) and adsorption-based methods, and to assess their prebiotic potential. The xylan was hydrolyzed with XynBTN63D at 40°C for 24 hours. The hydrolysate was purified using activated carbon with ethanol (10%–50%) as the eluent, followed by column chromatography. XOS composition was analyzed before and after purification using thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). Both pre- and post-purification products contained xylobiose (X2) and xylotriose (X3), while ethanol concentrations of 10%, 20%, and 30% were effective in removing residual xylan. Higher ethanol concentrations were less effective in XOS recovery. Activated carbon significantly improved the purity by eliminating impurities and enhancing X2 and X3separation. The results confirm that the enzyme operates with high specificity, producing oligosaccharides with potential applications in prebiotics and functional food industries. This study demonstrates the potential of coffee peel a widely available agricultural waste as a low-cost, sustainable lignocellulosic source for prebiotic XOS production. The unique application of XynBTN63D in combination with optimized ethanol-based adsorption contributes to the development of efficient XOS purification protocols.
Key words: Prebiotic; enzymatic hydrolysis; bioconversion; purification; lignocellulosic biomass
Prediction of coffee sensory attributes using near-infrared spectroscopy
Full text linkCup tasting is the traditional method for evaluating coffee beverage quality. However, sensory analysis has several limitations, including subjectivity, high costs and the challenge of establishing desirable limits for different quality attributes. Therefore, this study aimed to predict coffee sensory attributes based on near-infrared (NIR) spectra of roasted and ground coffee samples. For that, an experiment was conducted during the 2020-2021 harvest season in the Zona da Mata region of Minas Gerais State, Southeastern Brazil, involving seven arabica coffee fields. A total of 180 coffee samples were harvested, processed, and evaluated through sensory analysis following the Specialty Coffee Association protocol. Subsequently, regression models using NIR spectra (1000 to 2500 nm) coupled with Partial least squares (PLS) and PLS-OPS (ordered predictors selection) were developed. The PLS-OPS models yielded the best results, with correlation coefficients (rP) ranging from 0.78 to 0.82 and prediction errors (RMSEP) between 0.15 and 0.13 for aftertaste, overallperception, body, and balance. While predictions for aroma, flavor, and acidity require further improvement, the other attributes showed performance comparable to more complex analytical techniques. These findings demonstrate that NIR spectroscopy, combined with advanced chemometric modeling, offers a promising, cost-effective alternative for predicting coffee sensory quality.
Key words: Coffea arabica L.; cup quality analysis; digital agriculture; proximal sensing
Research Trends on Arabica Coffee: A Bibliometric Analysis
Full text linkCoffee, one of the world’s oldest and most popular drinks, has become a crucial agricultural commodity with significant economic, social, and environmental impacts. This study presents a comprehensive bibliometric analysis of Arabica coffee research, drawing from Scopus and Web of Science (WoS) databases from 1990 to 2024. Given Arabica coffee’s economic, environmental, and socio-cultural significance, scholarly attention has intensified across multiple disciplines, yet an integrated overview of the field remains limited. This research addresses that gap by analysing 7,520 unique records using ScientoPy and VOSviewer to evaluate publication trends, productive institutions, leading journals, contributing countries, and co-occurrence of author keywords. The findings reveal a substantial increase in research output, particularly since 2015, with Brazil emerging as the most prolific country and theUniversidade Federal de Lavras (UFLA) leading institutional contributions. While traditional journals continue to play a key role, newer outlets such as Foods and IOP Conference Series have seen notable recent activity. Keyword co-occurrence analysis identifies two broad thematic directions: established domains focused on plant pathology, biochemical composition (e.g., caffeine, chlorogenic acid), and genetics; and emerging themes including climate change adaptation, antioxidant activity, agroforestry, and quality-driven value chains. The study underscores a shift towards interdisciplinary, sustainability-oriented research driven by environmental challenges, market demands, and policy shifts. This analysis provides a robust platform for future research planning, identifying collaboration opportunities, and aligning academic inquiry with global development goals. Future directions include co-authorshipand citation network analysis, policy impact studies, and exploring digital innovations in Arabica coffee production systems.
Key words: Arabica coffee; agroforestry; sustainable agriculture; functional beverages; good agricultural practices (GAP)